They'll field questions on the president's budget request but can also expect to be grilled on world affairs, as the White House juggles multiple international issues.

From China's recent placement of an advanced surface-to-air missile system on a contested island in the South China Sea to North Korea's recent long-range missile test and the growing terrorist threat in Libya, there's no shortage of flashpoints.

The Pentagon has submitted a $582.7 billion budget request, but defense hawks in Congress want that figure to be higher, citing threats from Russia and from the Islamic State in Iraq and Syria. Expect fireworks as Republicans on those committees demand answers from the president's top defense and diplomatic officials.

There are also a number of other high-profile defense officials testifying on Capitol Hill.

Adm. Harry Harris, commander of U.S. Pacific Command, and Gen. Curtis Scaparrotti, commander of U.S. Forces Korea, will testify before the Senate Armed Services Committee on Tuesday and the House Armed Services Committee on Wednesday.

Also Tuesday, a Senate Armed Services subcommittee will look at military healthcare reform with both Pentagon officials and outside experts.

On Wednesday, a House Armed Services subcommittee will hold a hearing on Defense Department science and technology programs for fiscal 2017.

Another House Armed Services subcommittee will hear Wednesday about U.S. strategic forces from Brian McKeon, principal deputy undersecretary of Defense for policy, and Adm. Cecil Haney, commander of Strategic Command.

Later Wednesday, a House Armed Services subcommittee will hold a hearing on budgeting and structuring at the Defense Health Agency.

Also Wednesday, a House Foreign Affairs subpanel will hear from outside experts about Boko Haram.

On Thursday, the Senate Armed Services Committee will consider nominations for under Department and assistant secretary of Defense for manpower and reserve affairs.

Gen. Philip Breedlove, commander of U.S. European Command, will testify the same day before the House Armed Services Committee.

Later Thursday, a House Armed Services subcommittee will hold a hearing on the Navy's budget request.

House Armed Services will close out its week Friday with a subcommittee hearing on the Army's budget request and another on medical readiness.